1. Field of the Invention
The present invention relates to a method of burning petroleum coke dust in a burner flame having an intensive internal recirculation zone.
2. Description of the Prior Art
In the petrochemical industry, residues, such as petroleum coke, are produced which have a very high heating value and are therefore preferred for utilization of the thermal energy contained therein. In addition to the high heating value of approximately 32 MJ/kg, petroleum coke is also characterized by a low ash content of about 0.5 to 5% by weight. Despite the high heating value and the low ash content, the petroleum coke is not capable of ignition due to relatively small components of volatile constituents. Measures therefore must be taken, especially with regard to combustion, which assure a reliable ignition and subsequently a stable combustion.
As tests have shown, petroleum coke dust can be burned utilizing burners with which the prerequisites for the ignition of the petroleum coke dust and for a subsequent stable combustion are possible. The significant criterion for the burners utilized is the presence of a so-called internal recirculation zone of the burner flame, via which the ignition energy is delivered.
In a manner similar to coal dust, the petroleum coke can be burned in pulverized or dust form. The ignition energy can be delivered in one or two ways. The first way comprises providing the ignition energy via the internal recirculation zone from an independent energy carrier, for example natural gas. The second way comprises delivering the ignition energy from the petroleum coke dust itself, although in order to ignite the petroleum coke dust, special ignition conditions must be provided in the recirculation zone which is formed. Measures also must be provided which assure a stable and complete combustion subsequent to ignition.
It is therefore an object of the present invention to provide a method of being able to burn petroleum coke dust in a stable manner in burners of conventional construction in an internal recirculation zone of the burner flame.